slide 1 of 40 most numerous organisms on earth. slide 2 of 40 copyright pearson prentice hall “...

of 40Most numerous organisms on Earth

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Copyright Pearson Prentice Hall

“ Most Wanted and Least Wanted Posters

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BACTERIA:•Most numerous organisms on Earth•1st forms of life on Earth•All are prokaryotic

•General Traits of all prokaryotes:•Lack a nucleus and membrane bound organelles.•Unicellular (separate or in a colony)•Can be autotrophic or heterotrophic•Are microscopic

•300 side by side = printed period

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Bacteri is found EVERYWHERE…

fFood

Air

Soil

On and in our body

On all objects

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430,000 year old bacteria found in a fresh water lake in Antarctica

Deep Ocean

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Some bacteria are:

1. Aerobic-requires oxygen

2. Anaerobic-lives in the absence of oxygen

Example:-Clostridium botulinum-Causes botulism / food poison -found improperly canned foods, meat and shell fish

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Cell wall: -made up of Peptidoglygcan(protein/carb combo) -protects and gives shape to cell.

-antibiotics inhibit bacteria from forming cell walls so future bacteria can be destroyed by your immune system

Cell wall

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Cell Wall

Cell membraneCell membrane:

-regulates what goes into and out of the cell -contains enzymes that aid in all cellular reactions

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Outer covering that is sticky. Allows bacteria to adhere to surfaces and prevents WBC’s from engulfing them.

Capsule

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Capsule

Cytoplasm

Cytoplasm:-liquid

solution which suspends DNA and ribosomes

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Capsule

Cytoplasm

Ribosomes

Ribosomes:

-uses DNA’sinstructions to

make all proteins

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Capsule

Cytoplasm

Ribosomes

DNA

DNA: -genetic material -1 loop of DNA

-known as the nucleoid

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Plasmid: -found in some bacteria -small loops of DNA -code for extra but not essential traits.

Ex/ antibiotic resistence

Capsule

Cytoplasm

Ribosomes

DNA

Plasmid

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Capsule

Cytoplasm

Ribosomes

DNA

Plasmid

Sex pili

Sex pili:

-short proteins which bacteria use to pick up plasmids from environment or from another bacteria cell

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Capsule

Cytoplasm

Ribosomes

DNA

Plasmid

Sex piliFlagella

Flagella: -1 or more longwhip like tails used for movement.

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Movement

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Classifying Prokaryotes

E. coli, a Typical Eubacterium

Cell wall

Cell Membrane

Ribosomes

PiliDNAFlagellum

Capsule

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Endospores

Form when a bacterium produces a thick internal wall that encloses its DNA and some of its cytoplasm during unfavorable growth conditions.

Spores can remain dormant for months or years.

Spores allow bacteria to survive harsh conditions. (extreme heat, lack of moisture, etc…)

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Ideal Reproductive/Growth Conditions

-moisture-warmth-food source-darkness

Food and moistureWarm and darkness

Ideal warm, dark and moist environment with plenty of food?

The human body

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Bacteria can be:

1. Heterotrophic-uses other organisms as a food source.

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2. Saprophytic:

-live off dead matter-bacteria is the #1 decomposer

3. Autotrophic:

-makes their own food through photosynthesis.

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Reproduction

Binary fission

Binary Fission Bacteria copies its DNA and divides in half, producing two identical daughter cells.

Form of asexual reproduction

Takes about 20 min. in bacteria.

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Conjugation

During conjugation, a hollow bridge made up of the sex pili forms between two bacterial cells, and genes move from one cell to the other.

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Transformation:

When bacteria use their sex pili to pick up DNA from their environment.

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The GOOD……..

To make medicines

Oil eating bacteria

To make food

#1 decomposer

Sewage treatment

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The BAD………..Makes us

sick/causes illnesses

STD’s: Gonorrhea, SyphilisChlamydia, Botulism, LymesDisease, Pinkeye, Tuberculosis, Pneumonia

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Can they be stopped?

RefrigerationFreezing

Heat: canning, cooking, sterilization

Dehydration

Antiseptics

Antibiotics

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You go to the doctors with a sore throat……………..now what happens????

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The doctor has to classify the bacteria to know how to

treat it.

1. The doctor cultures/grows the bacteria.

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Identifying Prokaryotes

2. The doctor determines the shape of the bacteria.

Bacilli

Rod-shaped prokaryotes are called

bacilli.

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Spherical prokaryotes are called cocci.

Cocci

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Spiral and corkscrew-shaped

prokaryotes are called spirilla.

Spirilla

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3.

Thedoctor determinesthecolony formation:

Strept mean grows in a long chain.

Staph means grows in a cluster

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Can you identify these bacteria?

Steptococcus

Staphococcus

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4. The doctor stains the bacteria.

Two different types of cell walls are found in Eubacteria. A method called gram staining tells them apart.

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Gram-positive bacteria have thick cell walls with large amounts of peptidoglycan.

-stains purple-produces exotoxins

-released during life of bacteria

Gram-negative bacteria have thinner cell walls inside an outer lipid layer.

-stains pink-produces endotoxins

-released after bacteria dies

Each type treated with different antibiotics

slide 1 of 40 most numerous organisms on earth. slide 2 of 40 copyright pearson prentice hall “...

Documents

bacteria cell slide

earth slide

movement slide

nucleoid slide

immune system cell wall

cell walls

shell fish slide

printed period slide